Can't straighten out composite helix

[vakobo]

when i compose two helices in one and try to straighten it out to make an ideal helix, then parts of this helix go through themselves and stuck.

[spmm]

Hi, maybe check your clashing importance is not zero, and try the 'structure painter' it will make a perfect helix for you from the area you have selected if the secondary structure is helix, make sure to leave a bit of loop at other end. The shake and wiggle . Hope that helps.